noun phe·nan·thro·line \fə̇ˈnan(t)thrəˌlēn, -lə̇n\

Definition of phenanthroline



  1. :  any of three crystalline nitrogen bases C12H8N2 related to phenanthrene and derivable from ortho-, meta-, and para-phenylenediamine; di-aza-phenanthrene; especially :  the ortho or 1,10-isomer that forms a red coordination complex with ferrous ions useful as an oxidation-reduction indicator (as with potassium permanganate as oxidizing agent) because it becomes faint blue in the oxidized form

Love words? You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Join MWU now and get access to America’s largest dictionary, with:

  • 300,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Origin and Etymology of phenanthroline

International Scientific Vocabulary phenanthr- + quinoline

Seen and Heard

What made you want to look up phenanthroline? Please tell us where you read or heard it (including the quote, if possible).


to cast off or become cast off

Get Word of the Day daily email!